The present invention relates to a temperature controlled hot plate.
Temperature controlled hot plates are known in which there is provided a recess in the center of the hot plate for a temperature sensor. By a spring the sensor is pressed into engagement with a cooking utensil placed on the hot plate. An example of such a hot plate is given in the Swedish patent No. 448 508. In a hot plate of this kind, according to the principle of regulation used the parameter of regulation is the temperature prevailing on the bottom surface of the cooking utensil. When the control temperature has been reached the hot plate body, most often being made of cast iron, has a heat content stored which continues to supply heat to the cooking utensil even after the disconnection of the hot plate. This gives rise to undesirable overshoots in the control temperature graph of the hot plate.
As appears from the Swedish patent No. 446 243, for example, the heating of liquid in a cooking utensil to cooking temperature can be performed at maximum power up to a predetermined temperature and from this point the continued cooking can take place at this predetermined temperature without any appearance of overshoots in the control temperature graph. However, in connection with this heating process there is a demand for advanced electronic control arrangements to be provided which for cost reasons are considered unrealistic in common ranges and cooking hobs.
Another disadvantage in the arrangement described in the first-mentioned patent is the requirement for an operation to be performed in the hot plate for mounting of the temperature sensor which, in addition, has a relatively complex design with a cup-shaped thin plate which is to be pressed upwards into contact with a cooking utensil. Here, the arrangement is unnecessarily complicated and, accordingly, costly in relation to ordinary power-regulated hot plates.